when a PDF is signed instead of reloading the current pdf viewer with the new file a new window is opened with the new file.
Strangely enough, this was the most pressing issue that our testers complained about because this was very irritating for them.
I am giving this "high" priority so that it is above the "password manager" things.
I'm told that this is also what acrobat does, which is one of the reasons for the current approach.
Another is to make it clear to the user that there currently is 2 documents (foo.pdf and foo_signed.pdf).
Lastly, it was apparantly what was easiest to implement at that point in time.
I'm not sure neither of them are good reasons to keep doing it this way.